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Energy retrofitting of existing tunnels - from conceptualization to full-scale implementation
Get PDFL'abstract è presente nell'allegato / the abstract is in the attachmen
Sfruttamento geotermico di gallerie esistenti a fini di anti-icing stradale
No full textConsiderando sia le emissioni di dirette che quelle indirette, il settore delle costruzioni contribuisce a circa il 18% delle emissioni globali di CO2eq. Per raggoiungere l'obiettivo fissato dall'accordo di Parigi, le geostrutture energetiche possono rappresentare una soluzione per rendere il settore civile più eco-sostenibile in quanto in grado di produrre energia termica rinnovabile ed a basso impatto ambientale. Questo contributo descriverà i risultati di alcune analisi numeriche preliminari condotte per valutare l'attuabilità di un sistema di anti-icing geotermico che approvvigionerà calore da una galleria esistente strumentata per lo scambio di calore durante i lavori di rinnovo strutturale della stessa
Seizing the opportunity of energy retrofitting of existing tunnels
Get PDFEnergy tunnels have emerged as systems that can contribute to the production of clean, renewable thermal energy. Nevertheless, so far applications have been related almost exclusively to new tunnelling projects. Accordingly, no systematic methodologies for the heat exchange instrumentation of existing tunnels have been proposed up until now. Starting from the valuable experience gained from different energy tunnel testbeds worldwide, this paper proposes two approaches that would allow the thermal activation of the existing heritage of tunnels. Different solutions are conceived for both approaches to fit various existing tunnel decay contexts and diverse levels of refurbishment necessity. These are illustrated, outlining characteristics and advantages, describing expected installation details and issues and analysing the possibility of real implementations. The geothermal potential of such solutions is assessed through thermo-hydraulic numerical modelling. Finally, with the aim of investigating their economic attractiveness and profitability, a brief economic analysis is drawn up, considering the geothermal energy produced and the costs involved in installing and running the systems
A solar-collecting system for tunnel thermal storage
Get PDFDespite being resilient geostructures, a non-negligible amount of tunnels worldwide are approaching the end of their service life. This is mainly evident in Italy due to the agedness of most of the underground built environment. To address this issue, a plan to renovate existing motorway tunnels is underway to extend their serviceability. In this framework, a novel energy tunnel based anti-icing solar-collecting system is being implemented on a full scale in a motorway tunnel undergoing renovation. This envisages a geothermal serpentine embedded in the rehabilitated lining connected to other heat exchanger piping placed within the motorway pavement. Working in free-cooling mode, the system can take advantage of the thermal inertia of the ground behind the lining to store the solar heat collected through the motorway pavement, acting as a solar collector. The aim is to use this heat for anti-icing operations during the harshest periods of winter seasons.
This paper will illustrate the laboratory testing and numerical modelling needed to preliminarily assess the
functionality of the energy tunnel based anti-icing solar-collecting system
Numerical modelling of existing tunnels subjected to time dependent threats
No full textDealing with time-dependent phenomena during tunnel excavation and management is a complex topic that engineers and geologists need to face worldwide. Threats to tunnel stability are posed by the swelling/creep behaviour of geomaterials. These phenomena occur during the construction of the tunnel but can evolve for a long period after tunnel operation and can jeopardize the tunnel integrity with time. Although the topic of time-dependent behaviour has been repeatedly addressed in the literature, less attention has been paid to methodologies to deal with it during the serviceability of tunnels. Therefore, appropriate and reliable methods are needed to analyse and predict tunnel behaviour during their service life and/or refurbishment processes. This paper will focus on existing tunnels subjected to the time-dependent behaviour of the surrounding ground to identify the methodological approach for designing maintenance works and/or managing the associated risks. Examples from the Authors' experience are used to support the discussion
Anti-icing using the heat recovered in the Lagoscuro tunnel
Get PDFIn the context of promoting local energy sources with low environmental impact, energy geostructures are more and more being explored. This paper will describe an example of a technological system able to achieve the anti-icing of the motorway pavement through the exploitation of heat from the adjacent tunnel. Taking advantage of the current motorway refurbishment plan fostered by Autostrade per l'Italia (ASPI) and the activities planned for the Lagoscuro tunnel, located along the A26 motorway in the Genova province, the opportunity for geothermal energy exploitation is being tested in a full-scale prototype. The details of the experimental site setup will be revealed together with the characteristics of the pavement anti-icing solution
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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